/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/

This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it freely,
subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/

#include "btCollisionWorld.h"
#include "btCollisionDispatcher.h"
#include "btCollisionObject.h"
#include "btCollisionShape.h"
#include "btConvexShape.h"
#include "btGjkEpaPenetrationDepthSolver.h"
#include "btSphereShape.h" //for raycasting
#include "btBvhTriangleMeshShape.h" //for raycasting
#include "btRaycastCallback.h"
#include "btCompoundShape.h"
#include "btSubSimplexConvexCast.h"
#include "btGjkConvexCast.h"
#include "btContinuousConvexCollision.h"

#include "btBroadphaseInterface.h"
#include "btAabbUtil2.h"
#include "btQuickprof.h"
#include "btStackAlloc.h"

//#define USE_BRUTEFORCE_RAYBROADPHASE 1
//RECALCULATE_AABB is slower, but benefit is that you don't need to call 'stepSimulation'  or 'updateAabbs' before using a rayTest
//#define RECALCULATE_AABB_RAYCAST 1

//When the user doesn't provide dispatcher or broadphase, create basic versions (and delete them in destructor)
#include "btCollisionDispatcher.h"
#include "btSimpleBroadphase.h"
#include "btCollisionConfiguration.h"


btCollisionWorld::btCollisionWorld(btDispatcher* dispatcher,btBroadphaseInterface* pairCache, btCollisionConfiguration* collisionConfiguration)
:m_dispatcher1(dispatcher),
m_broadphasePairCache(pairCache),
m_debugDrawer(0)
{
    m_stackAlloc = collisionConfiguration->getStackAllocator();
    m_dispatchInfo.m_stackAllocator = m_stackAlloc;
}


btCollisionWorld::~btCollisionWorld()
{

    //clean up remaining objects
    int i;
    for (i=0;i<m_collisionObjects.size();i++)
    {
        btCollisionObject* collisionObject= m_collisionObjects[i];

        btBroadphaseProxy* bp = collisionObject->getBroadphaseHandle();
        if (bp)
        {
            //
            // only clear the cached algorithms
            //
            getBroadphase()->getOverlappingPairCache()->cleanProxyFromPairs(bp,m_dispatcher1);
            getBroadphase()->destroyProxy(bp,m_dispatcher1);
            collisionObject->setBroadphaseHandle(0);
        }
    }


}










void    btCollisionWorld::addCollisionObject(btCollisionObject* collisionObject,short int collisionFilterGroup,short int collisionFilterMask)
{

    //check that the object isn't already added
        btAssert( m_collisionObjects.findLinearSearch(collisionObject)  == m_collisionObjects.size());

        m_collisionObjects.push_back(collisionObject);

        //calculate new AABB
        btTransform trans = collisionObject->getWorldTransform();

        btVector3    minAabb;
        btVector3    maxAabb;
        collisionObject->getCollisionShape()->getAabb(trans,minAabb,maxAabb);

        int type = collisionObject->getCollisionShape()->getShapeType();
        collisionObject->setBroadphaseHandle( getBroadphase()->createProxy(
            minAabb,
            maxAabb,
            type,
            collisionObject,
            collisionFilterGroup,
            collisionFilterMask,
            m_dispatcher1,0
            ))    ;





}



void    btCollisionWorld::updateSingleAabb(btCollisionObject* colObj)
{
    btVector3 minAabb,maxAabb;
    colObj->getCollisionShape()->getAabb(colObj->getWorldTransform(), minAabb,maxAabb);
    //need to increase the aabb for contact thresholds
    btVector3 contactThreshold(gContactBreakingThreshold,gContactBreakingThreshold,gContactBreakingThreshold);
    minAabb -= contactThreshold;
    maxAabb += contactThreshold;

    btBroadphaseInterface* bp = (btBroadphaseInterface*)m_broadphasePairCache;

    //moving objects should be moderately sized, probably something wrong if not
    if ( colObj->isStaticObject() || ((maxAabb-minAabb).length2() < btScalar(1e12)))
    {
        bp->setAabb(colObj->getBroadphaseHandle(),minAabb,maxAabb, m_dispatcher1);
    } else
    {
        //something went wrong, investigate
        //this assert is unwanted in 3D modelers (danger of loosing work)
        colObj->setActivationState(DISABLE_SIMULATION);

        static bool reportMe = true;
        if (reportMe && m_debugDrawer)
        {
            reportMe = false;
            m_debugDrawer->reportErrorWarning("Overflow in AABB, object removed from simulation");
            m_debugDrawer->reportErrorWarning("If you can reproduce this, please email bugs@continuousphysics.com\n");
            m_debugDrawer->reportErrorWarning("Please include above information, your Platform, version of OS.\n");
            m_debugDrawer->reportErrorWarning("Thanks.\n");
        }
    }
}

void    btCollisionWorld::updateAabbs()
{
    BT_PROFILE("updateAabbs");

    btTransform predictedTrans;
    for ( int i=0;i<m_collisionObjects.size();i++)
    {
        btCollisionObject* colObj = m_collisionObjects[i];

        //only update aabb of active objects
        if (colObj->isActive())
        {
            updateSingleAabb(colObj);
        }
    }
}



void    btCollisionWorld::performDiscreteCollisionDetection()
{
    BT_PROFILE("performDiscreteCollisionDetection");

    btDispatcherInfo& dispatchInfo = getDispatchInfo();

    updateAabbs();

    {
        BT_PROFILE("calculateOverlappingPairs");
        m_broadphasePairCache->calculateOverlappingPairs(m_dispatcher1);
    }


    btDispatcher* dispatcher = getDispatcher();
    {
        BT_PROFILE("dispatchAllCollisionPairs");
        if (dispatcher)
            dispatcher->dispatchAllCollisionPairs(m_broadphasePairCache->getOverlappingPairCache(),dispatchInfo,m_dispatcher1);
    }

}



void    btCollisionWorld::removeCollisionObject(btCollisionObject* collisionObject)
{


    //bool removeFromBroadphase = false;

    {

        btBroadphaseProxy* bp = collisionObject->getBroadphaseHandle();
        if (bp)
        {
            //
            // only clear the cached algorithms
            //
            getBroadphase()->getOverlappingPairCache()->cleanProxyFromPairs(bp,m_dispatcher1);
            getBroadphase()->destroyProxy(bp,m_dispatcher1);
            collisionObject->setBroadphaseHandle(0);
        }
    }


    //swapremove
    m_collisionObjects.remove(collisionObject);

}



void    btCollisionWorld::rayTestSingle(const btTransform& rayFromTrans,const btTransform& rayToTrans,
                      btCollisionObject* collisionObject,
                      const btCollisionShape* collisionShape,
                      const btTransform& colObjWorldTransform,
                      RayResultCallback& resultCallback)
{
    btSphereShape pointShape(btScalar(0.0));
    pointShape.setMargin(0.f);
    const btConvexShape* castShape = &pointShape;

    if (collisionShape->isConvex())
    {
//        BT_PROFILE("rayTestConvex");
        btConvexCast::CastResult castResult;
        castResult.m_fraction = resultCallback.m_closestHitFraction;

        btConvexShape* convexShape = (btConvexShape*) collisionShape;
        btVoronoiSimplexSolver    simplexSolver;
#define USE_SUBSIMPLEX_CONVEX_CAST 1
#ifdef USE_SUBSIMPLEX_CONVEX_CAST
        btSubsimplexConvexCast convexCaster(castShape,convexShape,&simplexSolver);
#else
        //btGjkConvexCast    convexCaster(castShape,convexShape,&simplexSolver);
        //btContinuousConvexCollision convexCaster(castShape,convexShape,&simplexSolver,0);
#endif //#USE_SUBSIMPLEX_CONVEX_CAST

        if (convexCaster.calcTimeOfImpact(rayFromTrans,rayToTrans,colObjWorldTransform,colObjWorldTransform,castResult))
        {
            //add hit
            if (castResult.m_normal.length2() > btScalar(0.0001))
            {
                if (castResult.m_fraction < resultCallback.m_closestHitFraction)
                {
#ifdef USE_SUBSIMPLEX_CONVEX_CAST
                    //rotate normal into worldspace
                    castResult.m_normal = rayFromTrans.getBasis() * castResult.m_normal;
#endif //USE_SUBSIMPLEX_CONVEX_CAST

                    castResult.m_normal.normalize();
                    btCollisionWorld::LocalRayResult localRayResult
                        (
                            collisionObject,
                            0,
                            castResult.m_normal,
                            castResult.m_fraction
                        );

                    bool normalInWorldSpace = true;
                    resultCallback.addSingleResult(localRayResult, normalInWorldSpace);

                }
            }
        }
    } else {
        if (collisionShape->isConcave())
        {
//            BT_PROFILE("rayTestConcave");
            if (collisionShape->getShapeType()==TRIANGLE_MESH_SHAPE_PROXYTYPE)
            {
                ///optimized version for btBvhTriangleMeshShape
                btBvhTriangleMeshShape* triangleMesh = (btBvhTriangleMeshShape*)collisionShape;
                btTransform worldTocollisionObject = colObjWorldTransform.inverse();
                btVector3 rayFromLocal = worldTocollisionObject * rayFromTrans.getOrigin();
                btVector3 rayToLocal = worldTocollisionObject * rayToTrans.getOrigin();

                //ConvexCast::CastResult
                struct BridgeTriangleRaycastCallback : public btTriangleRaycastCallback
                {
                    btCollisionWorld::RayResultCallback* m_resultCallback;
                    btCollisionObject*    m_collisionObject;
                    btTriangleMeshShape*    m_triangleMesh;

               btTransform m_colObjWorldTransform;

                    BridgeTriangleRaycastCallback( const btVector3& from,const btVector3& to,
                        btCollisionWorld::RayResultCallback* resultCallback, btCollisionObject* collisionObject,btTriangleMeshShape*    triangleMesh,const btTransform& colObjWorldTransform):
                  //@BP Mod
                        btTriangleRaycastCallback(from,to, resultCallback->m_flags),
                            m_resultCallback(resultCallback),
                            m_collisionObject(collisionObject),
                            m_triangleMesh(triangleMesh),
                     m_colObjWorldTransform(colObjWorldTransform)
                        {
                        }


                    virtual btScalar reportHit(const btVector3& hitNormalLocal, btScalar hitFraction, int partId, int triangleIndex )
                    {
                        btCollisionWorld::LocalShapeInfo    shapeInfo;
                        shapeInfo.m_shapePart = partId;
                        shapeInfo.m_triangleIndex = triangleIndex;

                  btVector3 hitNormalWorld = m_colObjWorldTransform.getBasis() * hitNormalLocal;

                        btCollisionWorld::LocalRayResult rayResult
                        (m_collisionObject,
                            &shapeInfo,
                            hitNormalWorld,
                            hitFraction);

                        bool    normalInWorldSpace = true;
                        return m_resultCallback->addSingleResult(rayResult,normalInWorldSpace);
                    }

                };

                BridgeTriangleRaycastCallback rcb(rayFromLocal,rayToLocal,&resultCallback,collisionObject,triangleMesh,colObjWorldTransform);
                rcb.m_hitFraction = resultCallback.m_closestHitFraction;
                triangleMesh->performRaycast(&rcb,rayFromLocal,rayToLocal);
            } else
            {
                //generic (slower) case
                btConcaveShape* concaveShape = (btConcaveShape*)collisionShape;

                btTransform worldTocollisionObject = colObjWorldTransform.inverse();

                btVector3 rayFromLocal = worldTocollisionObject * rayFromTrans.getOrigin();
                btVector3 rayToLocal = worldTocollisionObject * rayToTrans.getOrigin();

                //ConvexCast::CastResult

                struct BridgeTriangleRaycastCallback : public btTriangleRaycastCallback
                {
                    btCollisionWorld::RayResultCallback* m_resultCallback;
                    btCollisionObject*    m_collisionObject;
                    btConcaveShape*    m_triangleMesh;

               btTransform m_colObjWorldTransform;

                    BridgeTriangleRaycastCallback( const btVector3& from,const btVector3& to,
                        btCollisionWorld::RayResultCallback* resultCallback, btCollisionObject* collisionObject,btConcaveShape*    triangleMesh, const btTransform& colObjWorldTransform):
                  //@BP Mod
                  btTriangleRaycastCallback(from,to, resultCallback->m_flags),
                            m_resultCallback(resultCallback),
                            m_collisionObject(collisionObject),
                            m_triangleMesh(triangleMesh),
                     m_colObjWorldTransform(colObjWorldTransform)
                        {
                        }


                    virtual btScalar reportHit(const btVector3& hitNormalLocal, btScalar hitFraction, int partId, int triangleIndex )
                    {
                        btCollisionWorld::LocalShapeInfo    shapeInfo;
                        shapeInfo.m_shapePart = partId;
                        shapeInfo.m_triangleIndex = triangleIndex;

                  btVector3 hitNormalWorld = m_colObjWorldTransform.getBasis() * hitNormalLocal;

                        btCollisionWorld::LocalRayResult rayResult
                        (m_collisionObject,
                            &shapeInfo,
                            hitNormalWorld,
                            hitFraction);

                        bool    normalInWorldSpace = true;
                        return m_resultCallback->addSingleResult(rayResult,normalInWorldSpace);
                    }

                };


                BridgeTriangleRaycastCallback    rcb(rayFromLocal,rayToLocal,&resultCallback,collisionObject,concaveShape, colObjWorldTransform);
                rcb.m_hitFraction = resultCallback.m_closestHitFraction;

                btVector3 rayAabbMinLocal = rayFromLocal;
                rayAabbMinLocal.setMin(rayToLocal);
                btVector3 rayAabbMaxLocal = rayFromLocal;
                rayAabbMaxLocal.setMax(rayToLocal);

                concaveShape->processAllTriangles(&rcb,rayAabbMinLocal,rayAabbMaxLocal);
            }
        } else {
//            BT_PROFILE("rayTestCompound");
            ///@todo: use AABB tree or other BVH acceleration structure, see btDbvt
            if (collisionShape->isCompound())
            {
                const btCompoundShape* compoundShape = static_cast<const btCompoundShape*>(collisionShape);
                int i=0;
                for (i=0;i<compoundShape->getNumChildShapes();i++)
                {
                    btTransform childTrans = compoundShape->getChildTransform(i);
                    const btCollisionShape* childCollisionShape = compoundShape->getChildShape(i);
                    btTransform childWorldTrans = colObjWorldTransform * childTrans;
                    // replace collision shape so that callback can determine the triangle
                    btCollisionShape* saveCollisionShape = collisionObject->getCollisionShape();
                    collisionObject->internalSetTemporaryCollisionShape((btCollisionShape*)childCollisionShape);
                    rayTestSingle(rayFromTrans,rayToTrans,
                        collisionObject,
                        childCollisionShape,
                        childWorldTrans,
                        resultCallback);
                    // restore
                    collisionObject->internalSetTemporaryCollisionShape(saveCollisionShape);
                }
            }
        }
    }
}

void    btCollisionWorld::objectQuerySingle(const btConvexShape* castShape,const btTransform& convexFromTrans,const btTransform& convexToTrans,
                      btCollisionObject* collisionObject,
                      const btCollisionShape* collisionShape,
                      const btTransform& colObjWorldTransform,
                      ConvexResultCallback& resultCallback, btScalar allowedPenetration)
{
    if (collisionShape->isConvex())
    {
        //BT_PROFILE("convexSweepConvex");
        btConvexCast::CastResult castResult;
        castResult.m_allowedPenetration = allowedPenetration;
        castResult.m_fraction = resultCallback.m_closestHitFraction;//btScalar(1.);//??

        btConvexShape* convexShape = (btConvexShape*) collisionShape;
        btVoronoiSimplexSolver    simplexSolver;
        btGjkEpaPenetrationDepthSolver    gjkEpaPenetrationSolver;

        btContinuousConvexCollision convexCaster1(castShape,convexShape,&simplexSolver,&gjkEpaPenetrationSolver);
        //btGjkConvexCast convexCaster2(castShape,convexShape,&simplexSolver);
        //btSubsimplexConvexCast convexCaster3(castShape,convexShape,&simplexSolver);

        btConvexCast* castPtr = &convexCaster1;



        if (castPtr->calcTimeOfImpact(convexFromTrans,convexToTrans,colObjWorldTransform,colObjWorldTransform,castResult))
        {
            //add hit
            if (castResult.m_normal.length2() > btScalar(0.0001))
            {
                if (castResult.m_fraction < resultCallback.m_closestHitFraction)
                {
                    castResult.m_normal.normalize();
                    btCollisionWorld::LocalConvexResult localConvexResult
                                (
                                    collisionObject,
                                    0,
                                    castResult.m_normal,
                                    castResult.m_hitPoint,
                                    castResult.m_fraction
                                );

                    bool normalInWorldSpace = true;
                    resultCallback.addSingleResult(localConvexResult, normalInWorldSpace);

                }
            }
        }
    } else {
        if (collisionShape->isConcave())
        {
            if (collisionShape->getShapeType()==TRIANGLE_MESH_SHAPE_PROXYTYPE)
            {
                //BT_PROFILE("convexSweepbtBvhTriangleMesh");
                btBvhTriangleMeshShape* triangleMesh = (btBvhTriangleMeshShape*)collisionShape;
                btTransform worldTocollisionObject = colObjWorldTransform.inverse();
                btVector3 convexFromLocal = worldTocollisionObject * convexFromTrans.getOrigin();
                btVector3 convexToLocal = worldTocollisionObject * convexToTrans.getOrigin();
                // rotation of box in local mesh space = MeshRotation^-1 * ConvexToRotation
                btTransform rotationXform = btTransform(worldTocollisionObject.getBasis() * convexToTrans.getBasis());

                //ConvexCast::CastResult
                struct BridgeTriangleConvexcastCallback : public btTriangleConvexcastCallback
                {
                    btCollisionWorld::ConvexResultCallback* m_resultCallback;
                    btCollisionObject*    m_collisionObject;
                    btTriangleMeshShape*    m_triangleMesh;

                    BridgeTriangleConvexcastCallback(const btConvexShape* castShape, const btTransform& from,const btTransform& to,
                        btCollisionWorld::ConvexResultCallback* resultCallback, btCollisionObject* collisionObject,btTriangleMeshShape*    triangleMesh, const btTransform& triangleToWorld):
                        btTriangleConvexcastCallback(castShape, from,to, triangleToWorld, triangleMesh->getMargin()),
                            m_resultCallback(resultCallback),
                            m_collisionObject(collisionObject),
                            m_triangleMesh(triangleMesh)
                        {
                        }


                    virtual btScalar reportHit(const btVector3& hitNormalLocal, const btVector3& hitPointLocal, btScalar hitFraction, int partId, int triangleIndex )
                    {
                        btCollisionWorld::LocalShapeInfo    shapeInfo;
                        shapeInfo.m_shapePart = partId;
                        shapeInfo.m_triangleIndex = triangleIndex;
                        if (hitFraction <= m_resultCallback->m_closestHitFraction)
                        {

                            btCollisionWorld::LocalConvexResult convexResult
                            (m_collisionObject,
                                &shapeInfo,
                                hitNormalLocal,
                                hitPointLocal,
                                hitFraction);

                            bool    normalInWorldSpace = true;


                            return m_resultCallback->addSingleResult(convexResult,normalInWorldSpace);
                        }
                        return hitFraction;
                    }

                };

                BridgeTriangleConvexcastCallback tccb(castShape, convexFromTrans,convexToTrans,&resultCallback,collisionObject,triangleMesh, colObjWorldTransform);
                tccb.m_hitFraction = resultCallback.m_closestHitFraction;
                btVector3 boxMinLocal, boxMaxLocal;
                castShape->getAabb(rotationXform, boxMinLocal, boxMaxLocal);
                triangleMesh->performConvexcast(&tccb,convexFromLocal,convexToLocal,boxMinLocal, boxMaxLocal);
            } else
            {
                //BT_PROFILE("convexSweepConcave");
                btConcaveShape* concaveShape = (btConcaveShape*)collisionShape;
                btTransform worldTocollisionObject = colObjWorldTransform.inverse();
                btVector3 convexFromLocal = worldTocollisionObject * convexFromTrans.getOrigin();
                btVector3 convexToLocal = worldTocollisionObject * convexToTrans.getOrigin();
                // rotation of box in local mesh space = MeshRotation^-1 * ConvexToRotation
                btTransform rotationXform = btTransform(worldTocollisionObject.getBasis() * convexToTrans.getBasis());

                //ConvexCast::CastResult
                struct BridgeTriangleConvexcastCallback : public btTriangleConvexcastCallback
                {
                    btCollisionWorld::ConvexResultCallback* m_resultCallback;
                    btCollisionObject*    m_collisionObject;
                    btConcaveShape*    m_triangleMesh;

                    BridgeTriangleConvexcastCallback(const btConvexShape* castShape, const btTransform& from,const btTransform& to,
                        btCollisionWorld::ConvexResultCallback* resultCallback, btCollisionObject* collisionObject,btConcaveShape*    triangleMesh, const btTransform& triangleToWorld):
                        btTriangleConvexcastCallback(castShape, from,to, triangleToWorld, triangleMesh->getMargin()),
                            m_resultCallback(resultCallback),
                            m_collisionObject(collisionObject),
                            m_triangleMesh(triangleMesh)
                        {
                        }


                    virtual btScalar reportHit(const btVector3& hitNormalLocal, const btVector3& hitPointLocal, btScalar hitFraction, int partId, int triangleIndex )
                    {
                        btCollisionWorld::LocalShapeInfo    shapeInfo;
                        shapeInfo.m_shapePart = partId;
                        shapeInfo.m_triangleIndex = triangleIndex;
                        if (hitFraction <= m_resultCallback->m_closestHitFraction)
                        {

                            btCollisionWorld::LocalConvexResult convexResult
                            (m_collisionObject,
                                &shapeInfo,
                                hitNormalLocal,
                                hitPointLocal,
                                hitFraction);

                            bool    normalInWorldSpace = false;

                            return m_resultCallback->addSingleResult(convexResult,normalInWorldSpace);
                        }
                        return hitFraction;
                    }

                };

                BridgeTriangleConvexcastCallback tccb(castShape, convexFromTrans,convexToTrans,&resultCallback,collisionObject,concaveShape, colObjWorldTransform);
                tccb.m_hitFraction = resultCallback.m_closestHitFraction;
                btVector3 boxMinLocal, boxMaxLocal;
                castShape->getAabb(rotationXform, boxMinLocal, boxMaxLocal);

                btVector3 rayAabbMinLocal = convexFromLocal;
                rayAabbMinLocal.setMin(convexToLocal);
                btVector3 rayAabbMaxLocal = convexFromLocal;
                rayAabbMaxLocal.setMax(convexToLocal);
                rayAabbMinLocal += boxMinLocal;
                rayAabbMaxLocal += boxMaxLocal;
                concaveShape->processAllTriangles(&tccb,rayAabbMinLocal,rayAabbMaxLocal);
            }
        } else {
            ///@todo : use AABB tree or other BVH acceleration structure!
            if (collisionShape->isCompound())
            {
                BT_PROFILE("convexSweepCompound");
                const btCompoundShape* compoundShape = static_cast<const btCompoundShape*>(collisionShape);
                int i=0;
                for (i=0;i<compoundShape->getNumChildShapes();i++)
                {
                    btTransform childTrans = compoundShape->getChildTransform(i);
                    const btCollisionShape* childCollisionShape = compoundShape->getChildShape(i);
                    btTransform childWorldTrans = colObjWorldTransform * childTrans;
                    // replace collision shape so that callback can determine the triangle
                    btCollisionShape* saveCollisionShape = collisionObject->getCollisionShape();
                    collisionObject->internalSetTemporaryCollisionShape((btCollisionShape*)childCollisionShape);
                    objectQuerySingle(castShape, convexFromTrans,convexToTrans,
                        collisionObject,
                        childCollisionShape,
                        childWorldTrans,
                        resultCallback, allowedPenetration);
                    // restore
                    collisionObject->internalSetTemporaryCollisionShape(saveCollisionShape);
                }
            }
        }
    }
}


struct btSingleRayCallback : public btBroadphaseRayCallback
{

    btVector3    m_rayFromWorld;
    btVector3    m_rayToWorld;
    btTransform    m_rayFromTrans;
    btTransform    m_rayToTrans;
    btVector3    m_hitNormal;

    const btCollisionWorld*    m_world;
    btCollisionWorld::RayResultCallback&    m_resultCallback;

    btSingleRayCallback(const btVector3& rayFromWorld,const btVector3& rayToWorld,const btCollisionWorld* world,btCollisionWorld::RayResultCallback& resultCallback)
    :m_rayFromWorld(rayFromWorld),
    m_rayToWorld(rayToWorld),
    m_world(world),
    m_resultCallback(resultCallback)
    {
        m_rayFromTrans.setIdentity();
        m_rayFromTrans.setOrigin(m_rayFromWorld);
        m_rayToTrans.setIdentity();
        m_rayToTrans.setOrigin(m_rayToWorld);

        btVector3 rayDir = (rayToWorld-rayFromWorld);

        rayDir.normalize ();
        ///what about division by zero? --> just set rayDirection[i] to INF/BT_LARGE_FLOAT
        m_rayDirectionInverse[0] = rayDir[0] == btScalar(0.0) ? btScalar(BT_LARGE_FLOAT) : btScalar(1.0) / rayDir[0];
        m_rayDirectionInverse[1] = rayDir[1] == btScalar(0.0) ? btScalar(BT_LARGE_FLOAT) : btScalar(1.0) / rayDir[1];
        m_rayDirectionInverse[2] = rayDir[2] == btScalar(0.0) ? btScalar(BT_LARGE_FLOAT) : btScalar(1.0) / rayDir[2];
        m_signs[0] = m_rayDirectionInverse[0] < 0.0;
        m_signs[1] = m_rayDirectionInverse[1] < 0.0;
        m_signs[2] = m_rayDirectionInverse[2] < 0.0;

        m_lambda_max = rayDir.dot(m_rayToWorld-m_rayFromWorld);

    }



    virtual bool    process(const btBroadphaseProxy* proxy)
    {
        ///terminate further ray tests, once the closestHitFraction reached zero
        if (m_resultCallback.m_closestHitFraction == btScalar(0.f))
            return false;

        btCollisionObject*    collisionObject = (btCollisionObject*)proxy->m_clientObject;

        //only perform raycast if filterMask matches
        if(m_resultCallback.needsCollision(collisionObject->getBroadphaseHandle()))
        {
            //RigidcollisionObject* collisionObject = ctrl->GetRigidcollisionObject();
            //btVector3 collisionObjectAabbMin,collisionObjectAabbMax;
#if 0
#ifdef RECALCULATE_AABB
            btVector3 collisionObjectAabbMin,collisionObjectAabbMax;
            collisionObject->getCollisionShape()->getAabb(collisionObject->getWorldTransform(),collisionObjectAabbMin,collisionObjectAabbMax);
#else
            //getBroadphase()->getAabb(collisionObject->getBroadphaseHandle(),collisionObjectAabbMin,collisionObjectAabbMax);
            const btVector3& collisionObjectAabbMin = collisionObject->getBroadphaseHandle()->m_aabbMin;
            const btVector3& collisionObjectAabbMax = collisionObject->getBroadphaseHandle()->m_aabbMax;
#endif
#endif
            //btScalar hitLambda = m_resultCallback.m_closestHitFraction;
            //culling already done by broadphase
            //if (btRayAabb(m_rayFromWorld,m_rayToWorld,collisionObjectAabbMin,collisionObjectAabbMax,hitLambda,m_hitNormal))
            {
                m_world->rayTestSingle(m_rayFromTrans,m_rayToTrans,
                    collisionObject,
                        collisionObject->getCollisionShape(),
                        collisionObject->getWorldTransform(),
                        m_resultCallback);
            }
        }
        return true;
    }
};

void    btCollisionWorld::rayTest(const btVector3& rayFromWorld, const btVector3& rayToWorld, RayResultCallback& resultCallback) const
{
    BT_PROFILE("rayTest");
    /// use the broadphase to accelerate the search for objects, based on their aabb
    /// and for each object with ray-aabb overlap, perform an exact ray test
    btSingleRayCallback rayCB(rayFromWorld,rayToWorld,this,resultCallback);

#ifndef USE_BRUTEFORCE_RAYBROADPHASE
    m_broadphasePairCache->rayTest(rayFromWorld,rayToWorld,rayCB);
#else
    for (int i=0;i<this->getNumCollisionObjects();i++)
    {
        rayCB.process(m_collisionObjects[i]->getBroadphaseHandle());
    }
#endif //USE_BRUTEFORCE_RAYBROADPHASE

}


struct btSingleSweepCallback : public btBroadphaseRayCallback
{

    btTransform    m_convexFromTrans;
    btTransform    m_convexToTrans;
    btVector3    m_hitNormal;
    const btCollisionWorld*    m_world;
    btCollisionWorld::ConvexResultCallback&    m_resultCallback;
    btScalar    m_allowedCcdPenetration;
    const btConvexShape* m_castShape;


    btSingleSweepCallback(const btConvexShape* castShape, const btTransform& convexFromTrans,const btTransform& convexToTrans,const btCollisionWorld* world,btCollisionWorld::ConvexResultCallback& resultCallback,btScalar allowedPenetration)
        :m_convexFromTrans(convexFromTrans),
        m_convexToTrans(convexToTrans),
        m_world(world),
        m_resultCallback(resultCallback),
        m_allowedCcdPenetration(allowedPenetration),
        m_castShape(castShape)
    {
        btVector3 unnormalizedRayDir = (m_convexToTrans.getOrigin()-m_convexFromTrans.getOrigin());
        btVector3 rayDir = unnormalizedRayDir.normalized();
        ///what about division by zero? --> just set rayDirection[i] to INF/BT_LARGE_FLOAT
        m_rayDirectionInverse[0] = rayDir[0] == btScalar(0.0) ? btScalar(BT_LARGE_FLOAT) : btScalar(1.0) / rayDir[0];
        m_rayDirectionInverse[1] = rayDir[1] == btScalar(0.0) ? btScalar(BT_LARGE_FLOAT) : btScalar(1.0) / rayDir[1];
        m_rayDirectionInverse[2] = rayDir[2] == btScalar(0.0) ? btScalar(BT_LARGE_FLOAT) : btScalar(1.0) / rayDir[2];
        m_signs[0] = m_rayDirectionInverse[0] < 0.0;
        m_signs[1] = m_rayDirectionInverse[1] < 0.0;
        m_signs[2] = m_rayDirectionInverse[2] < 0.0;

        m_lambda_max = rayDir.dot(unnormalizedRayDir);

    }

    virtual bool    process(const btBroadphaseProxy* proxy)
    {
        ///terminate further convex sweep tests, once the closestHitFraction reached zero
        if (m_resultCallback.m_closestHitFraction == btScalar(0.f))
            return false;

        btCollisionObject*    collisionObject = (btCollisionObject*)proxy->m_clientObject;

        //only perform raycast if filterMask matches
        if(m_resultCallback.needsCollision(collisionObject->getBroadphaseHandle())) {
            //RigidcollisionObject* collisionObject = ctrl->GetRigidcollisionObject();
            m_world->objectQuerySingle(m_castShape, m_convexFromTrans,m_convexToTrans,
                    collisionObject,
                        collisionObject->getCollisionShape(),
                        collisionObject->getWorldTransform(),
                        m_resultCallback,
                        m_allowedCcdPenetration);
        }

        return true;
    }
};



void    btCollisionWorld::convexSweepTest(const btConvexShape* castShape, const btTransform& convexFromWorld, const btTransform& convexToWorld, ConvexResultCallback& resultCallback, btScalar allowedCcdPenetration) const
{

    BT_PROFILE("convexSweepTest");
    /// use the broadphase to accelerate the search for objects, based on their aabb
    /// and for each object with ray-aabb overlap, perform an exact ray test
    /// unfortunately the implementation for rayTest and convexSweepTest duplicated, albeit practically identical



    btTransform    convexFromTrans,convexToTrans;
    convexFromTrans = convexFromWorld;
    convexToTrans = convexToWorld;
    btVector3 castShapeAabbMin, castShapeAabbMax;
    /* Compute AABB that encompasses angular movement */
    {
        btVector3 linVel, angVel;
        btTransformUtil::calculateVelocity (convexFromTrans, convexToTrans, 1.0, linVel, angVel);
        btVector3 zeroLinVel;
        zeroLinVel.setValue(0,0,0);
        btTransform R;
        R.setIdentity ();
        R.setRotation (convexFromTrans.getRotation());
        castShape->calculateTemporalAabb (R, zeroLinVel, angVel, 1.0, castShapeAabbMin, castShapeAabbMax);
    }

#ifndef USE_BRUTEFORCE_RAYBROADPHASE

    btSingleSweepCallback    convexCB(castShape,convexFromWorld,convexToWorld,this,resultCallback,allowedCcdPenetration);

    m_broadphasePairCache->rayTest(convexFromTrans.getOrigin(),convexToTrans.getOrigin(),convexCB,castShapeAabbMin,castShapeAabbMax);

#else
    /// go over all objects, and if the ray intersects their aabb + cast shape aabb,
    // do a ray-shape query using convexCaster (CCD)
    int i;
    for (i=0;i<m_collisionObjects.size();i++)
    {
        btCollisionObject*    collisionObject= m_collisionObjects[i];
        //only perform raycast if filterMask matches
        if(resultCallback.needsCollision(collisionObject->getBroadphaseHandle())) {
            //RigidcollisionObject* collisionObject = ctrl->GetRigidcollisionObject();
            btVector3 collisionObjectAabbMin,collisionObjectAabbMax;
            collisionObject->getCollisionShape()->getAabb(collisionObject->getWorldTransform(),collisionObjectAabbMin,collisionObjectAabbMax);
            AabbExpand (collisionObjectAabbMin, collisionObjectAabbMax, castShapeAabbMin, castShapeAabbMax);
            btScalar hitLambda = btScalar(1.); //could use resultCallback.m_closestHitFraction, but needs testing
            btVector3 hitNormal;
            if (btRayAabb(convexFromWorld.getOrigin(),convexToWorld.getOrigin(),collisionObjectAabbMin,collisionObjectAabbMax,hitLambda,hitNormal))
            {
                objectQuerySingle(castShape, convexFromTrans,convexToTrans,
                    collisionObject,
                        collisionObject->getCollisionShape(),
                        collisionObject->getWorldTransform(),
                        resultCallback,
                        allowedCcdPenetration);
            }
        }
    }
#endif //USE_BRUTEFORCE_RAYBROADPHASE
}
